The internal combustion engine has been the subject of many improvements and developments over the past century. With increasing oil prices, and dwindling oil reserves, it is desirable to make the internal combustion engine more efficient than it currently is.
Furthermore, the internal combustion engine gives off exhaust gases that can be harmful to the environment. By improving the efficiency of the internal combustion engine, a quantity of exhaust gas given off by an internal combustion engine is reduced.
Improving the efficiency of the internal combustion engine therefore has two beneficial effects: The first is that the engine will use less fuel and therefore be more economical, and the second is that the engine will emit less exhaust gas, and therefore be less harmful to the environment.
One way to improve the efficiency of the internal combustion engine is to improve the air/fuel mixture in the combustion chamber. The air/fuel mixture is regulated to a large extent by either direct injection of the fuel into air in the combustion chamber of the engine cylinder on the compression stroke or indirect injection of the fuel into the air prior to it entering the cylinder. The air/fuel mixture can also be regulated by a carburetor, which mixes the air and fuel prior to the air/fuel mixture passing down an inlet manifold into the cylinder. In all cases the fuel is mixed with air in the form of droplets of fuel carried in an air flow into the combustion chamber of a internal combustion engine. During the combustion process the size and dispersal of the fuel droplets determines the efficiency of the burn and the energy released and so the efficiency of the engine.
Ways of improving the mixture include improving the atomization of the fuel in the air/fuel mixture, and increasing the turbulence of the air/fuel mixture.
Atomization of fuel can be improved by using heat from the engine block to increase the degree of atomization. Further methods of improving atomization of fuel include having vanes or blades that cause liquid fuel droplets to fragment on impact with the vanes or blades and form smaller droplets, thereby improving the air/fuel mixture.
Another way of improving the air/fuel mixture is to generate a vortex in the air/fuel mixture. US2003/015049 discloses a vortex generator for an engine. The vortex generator includes a tubular body with a plurality of curved blades. When moving air passes through the tubular body the curved blades redirect the air to form a vortex, such that the air swirls around an axis of a main length of the tubular body.
However, the vortex generator described is not suitable for an internal combustion engine having a throttle. The vortex generator is described as being located before an air filter, or between the air filter and the engine. Where the vortex generator is disposed upstream of an air filter, then the air filter will substantially destroy the vortex. Where the vortex generator is disposed downstream of the air filter, the swirling air will mix with the fuel and enter the engine. However, for an internal combustion engine that is required to be used at different speeds, in particular internal combustion engines used in vehicles, a throttle is required. The throttle, when closed or partially closed, would substantially destroy the vortex, thereby reducing the benefits of having the swirling airflow.
Referring to FIG. 1 herein, there is illustrated schematically a prior art internal combustion engine. In FIG. 1A, the internal combustion engine comprises a carburetor 101, a throttle 102, an inlet manifold 103 and the engine itself 104. In FIG. 1B, the internal combustion engine comprises an indirect injector 105. In FIG. 1C, the internal combustion engine comprises a direct injector 106.
Referring to FIG. 1A, the carburetor 101 is configured to mix air and fuel in the correct proportions to form a combustible mixture. The carburetor 101 essentially comprises at least one jet discharging the fuel into an airstream under the pressure difference created by the velocity of the air as it flows through a nozzle shaped construction. The throttle 102 allows a user to control the quantity of air/fuel mixture that is drawn into the combustion chamber of the engine 104. The inlet manifold 103 allows the air/fuel mixture to be drawn into the desired chambers of the engine 104. The engine 104 is where combustion of the air/fuel mixture takes place, converting the chemical energy of the air/fuel mixture into kinetic energy.
Referring to FIG. 1B, the indirect injection 105 system comprises at least one jet discharging fuel under pressure through an injector nozzle. Fuel is injected into the manifold 103 at a point before an inlet valve to a combustion chamber in the engine 104. A carburetor 101 is therefore nor required.
Referring to FIG. 1C, the direct injection system 106 discharges fuel directly into the air inside a cylinder of the engine 104. A carburetor 101 is therefore not required.